Do I Need Tax Forms for My 401(k): W-2, 1099-R, and 5329

Your 401(k) can generate up to four different tax forms in a given year, and which ones land in your mailbox depends entirely on what happened in the account. Contributions ride along on your W-2. Any money that left the plan produces a 1099-R. A rollover into an IRA adds a Form 5498. Early withdrawals, missed required distributions, and some corrections pull in Form 5329. A loan in good standing produces nothing at all. Here is what each of the tax forms for a 401(k) does, when to expect it, and how it affects your return.

Contributions: Your W-2 Is the Only Form You Get

There is no separate tax form for the money you put into your 401(k) through payroll. It is already reported on the Form W-2 your employer sends you in January. Look at Box 12.

Pre-tax contributions appear with Code D. The amount has already been removed from the taxable wages in Box 1, so you do not claim a separate deduction anywhere on your return.¹ Roth 401(k) contributions carry Code AA. Because Roth money is contributed after tax, it does not reduce Box 1.²

Employer matching and profit-sharing contributions do not show up on the W-2. The plan administrator tracks those internally, and they only surface on a tax form when the money eventually comes out.

Compare the Box 12 totals against your final pay stub. If they disagree, call payroll before you file. And if you worked for more than one employer in the same year, add the Code D and Code AA amounts across every W-2. Going over the annual elective deferral limit is the single most common mistake job-changers make, and it creates a filing problem you have to fix by April 15.

1099-R: The Form for Anything That Left the Account

Any distribution from your 401(k) produces a Form 1099-R from the plan administrator, sent by January 31 of the following year.³ Four boxes do the real work:

Box 1 shows the gross distribution before any withholding.
Box 2a shows the taxable amount. For a traditional 401(k), this usually matches Box 1.
Box 4 shows the federal income tax the plan withheld when it processed the payment.
Box 7 carries a one- or two-character distribution code that tells the IRS what kind of distribution this was.

The code in Box 7 drives everything else. A few you are likely to see:

Code 7 is a normal distribution taken at or after 59½. Required minimum distributions carry this same code.
Code 1 is an early distribution with no known exception to the 10% penalty.
Code G is a direct rollover to another plan or IRA. Box 2a should read zero.
Code B flags a distribution from a designated Roth account.
Code 4 is a death benefit paid to a beneficiary. The 10% penalty never applies.
Codes 8 and P are for corrective distributions of excess contributions.

Check the code before you enter anything on your return. A wrong code on the 1099-R can cost you real money, and plan administrators do occasionally issue corrections.

Roth 401(k) Distributions

A qualified Roth 401(k) distribution is tax-free. To qualify, you have to be at least 59½ (or disabled, or deceased), and at least five tax years must have passed since your first Roth 401(k) contribution.³ When those conditions are met, Box 2a should be zero or reduced. If they are not met, the earnings portion is taxable and the early withdrawal penalty may still apply. Either way, you still receive a 1099-R.

Required Minimum Distributions

Starting at age 73, the IRS requires annual withdrawals from a traditional 401(k). RMDs come through on the 1099-R with Code 7, no different from any other normal distribution.³ If you are still working at your current employer and do not own more than 5% of the company, you can delay RMDs from that employer’s plan until the year you retire. The exception does not extend to IRAs or to 401(k) accounts left with former employers.⁴ Missing an RMD triggers a 25% excise tax on the shortfall, which drops to 10% if you correct the mistake within two years. The penalty is reported on Form 5329.

Form 5329: Penalties and Exceptions

Form 5329 is where you handle two things: the 10% additional tax on early distributions, and the excise tax on missed RMDs. You file it with your return.

If you took money out before 59½, the 1099-R normally shows Code 1 unless the plan administrator knew a specific exception applied. Several situations exempt you from the 10% penalty even when the box code does not reflect them, including separation from service in or after the year you turn 55, total and permanent disability, substantially equal periodic payments over your life expectancy, unreimbursed medical expenses above 7.5% of AGI, distributions under a qualified domestic relations order, and distributions to satisfy an IRS levy.⁵ SECURE 2.0 added additional carve-outs, including a $1,000 annual emergency personal expense distribution and distributions for domestic abuse victims. If any of these fit your situation, use Form 5329 to claim the exception, even when Box 7 shows Code 1.

Some states also charge their own additional tax on early distributions, so the federal 10% may not be the whole penalty.

Rollovers: 1099-R Plus a Form 5498

Moving money from a 401(k) to another retirement account is not taxable when done correctly, but the IRS still sees the transaction.

In a direct rollover, the plan sends your balance straight to the receiving account. The old plan issues a 1099-R with Code G in Box 7 and Box 2a at zero.³ You report the rollover on Form 1040. No tax is owed. If the money went into an IRA, the receiving custodian issues a Form 5498 to document the rollover contribution. Form 5498 is informational, and copies go to you and to the IRS.⁶

An indirect rollover works differently. The plan writes a check to you, withholds 20% for federal taxes, and gives you 60 days to deposit the full pre-withholding amount into a new eligible retirement account.⁷ To roll over a $50,000 distribution in full, you have to come up with the withheld $10,000 from other funds and deposit $50,000. You get the $10,000 back when you file. The 1099-R will not carry Code G; you report the amount as a rollover on Form 1040 to show the IRS it was not taxable. Miss the 60-day window and the whole distribution becomes taxable income.⁸

401(k) Loans: No Form Unless You Default

A 401(k) loan that follows the plan’s rules produces no tax form. The IRS treats it as an internal transaction. No 1099-R, no reporting on your return.

The maximum loan is the lesser of $50,000 or 50% of your vested balance, and repayment normally has to happen within five years through level payments made at least quarterly.⁹ Loans used to buy a primary residence can have a longer term if the plan allows it.

Default changes everything. If you stop making payments, or you leave the job with an unpaid balance, the outstanding amount plus accrued interest becomes a deemed distribution. The plan issues a 1099-R for that amount, it gets added to your taxable income for the year, and if you are under 59½ the 10% early withdrawal penalty applies on top.¹⁰

Fixing an Excess Contribution

Deferring more than the annual limit produces its own form. If your Box 12 totals across multiple W-2s add up to more than the elective deferral limit, contact your plan administrator and ask for a corrective distribution of the excess plus earnings. The deadline is April 15 of the following year, and it does not move even if you file an extension.¹¹

The corrective distribution comes back on a 1099-R. Code 8 in Box 7 means the earnings are taxable in the year distributed. Code P means they are taxable in the prior year.³ Miss the April 15 deadline and the excess is taxed twice: once now, and again when you eventually take the money out.

Form 5500-EZ for Solo 401(k) Owners

If you are self-employed and run a one-participant 401(k), there is an additional filing employees with employer-sponsored plans never see. Once total plan assets exceed $250,000 at the end of the plan year, you must file Form 5500-EZ. The deadline for a calendar-year plan is July 31.¹² You also have to file a final 5500-EZ when you close the plan, no matter what the balance is. Late filings run $250 per day up to $150,000 per plan year, so this is not a form to overlook.

Below the $250,000 threshold, no filing is required, but keep records of contributions, earnings, and any loan balances in case the IRS asks.

1
Internal Revenue Service. Common Errors on Form W-2 Codes for Retirement Plans
2
Internal Revenue Service. Topic No. 424, 401(k) Plans
3
Internal Revenue Service. 2025 Instructions for Forms 1099-R and 5498
4
Internal Revenue Service. Retirement Plan and IRA Required Minimum Distributions FAQs
5
Internal Revenue Service. Retirement Topics – Exceptions to Tax on Early Distributions
6
Internal Revenue Service. About Form 5498, IRA Contribution Information (Info Copy Only)
7
Internal Revenue Service. Topic No. 413, Rollovers From Retirement Plans
8
Internal Revenue Service. Rollovers of Retirement Plan and IRA Distributions
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Internal Revenue Service. Retirement Plans FAQs Regarding Loans
10
Internal Revenue Service. Fixing Common Plan Mistakes – Plan Loan Failures and Deemed Distributions
11
Internal Revenue Service. Consequences to a Participant Who Makes Excess Deferrals to a 401(k) Plan
12
Internal Revenue Service. 2025 Instructions for Form 5500-EZ